The firehouse reacts to some exciting news; a mysterious stranger arrives, and a shocking call takes Severide's breath away.
Severide and Casey try to find the best fit for Kidd; Ritter, Gallo and Violet help plan an event for Mouch.
A mysterious caller who is in danger relies on Kidd to help save her and her brother; the firehouse helps Cruz get ready for fatherhood.
A fire breaks out at a pet food factory, and Casey and Severide help the owner, Pete, get to the bottom of it; the annual garage sale takes place at 51 and everyone is on edge.
Archer and Choi respond to a scene that brings back some bad memories; when Carol's condition worsens, Manning is willing to do whatever it takes to get her mum feeling better.